[PvK]

I think it can help to have several smaller squads under different commanders, sometimes. One consideration is that when the leader dies or routs, their troops usually do too. So if a huge number of men are under one leader, there is the risk of a mass retreat. The same is true of ordinary casualties - there is still some chance of a huge group routing - all eggs in one basket.

With units in smaller Groups, you can also get an effect where a small group that has been fighting routs, but other fresh Groups have no morale check at all, and fill in the gap. Since the routed units are likely to be wounded, this can actually reduce your overall casualties from a battle - sometimes fleeing to fight another day is a good thing - sticking around while nearly dead often isn't a good idea.

PvK